Cooling fan



FIG. 1 is a front elevational view of the cooling fan showing my new design;

FIG. 2 is an elevational view of one side thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is an elevational view of the other side thereof;

FIG. 5 is a top plan view thereof; and,

FIG. 6 is a bottom plan view thereof. 

The ornamental design for a cooling fan, as shown and described. 